The social-networking giant raised $500 million from Goldman Sachs Group Inc. and Russian firm Digital Sky Technologies, putting its valuation at $50 billion, the Journal’s Anupreeta Das confirmed. The New York Times had earlier reported the investment.

Does that number make sense? First, let’s compare Facebook’s valuation to the market capitalization of other Internet companies — Yahoo, EBay, Amazon and Google. Yahoo comes in at $21 billion, and Google is at about $190 billion. (Sure, it’s not apples to apples. Among other things, the other companies are more mature. And Amazon and EBay, as e-commerce companies, aren’t competing for Web surfers’ eyeballs the way Google and Yahoo are. But still. Worth a look.)